Roco Rescue



1910.147 LOTO vs. 1910.146 Isolation

Wednesday, July 06, 2011

Question:  If I close and Lockout/Tagout the main valve on the natural gas line supplying a boiler unit – does this satisfy OSHA’s requirement for eliminating the hazard of a permit required confined space?

Answer:  No, it does not. You are asking a question that we address quite often and it reveals some misconceptions regarding “eliminating” or “isolating” the permit space from hazards. Lockout/Tagout (LOTO) procedures are covered in OSHA’s 1910.147 “Control of Hazardous Energy (Lockout/Tagout).

” Many times this regulation is incorrectly referenced when addressing permit space hazards that are not covered by this regulation.
OSHA’s 1910.147 LOTO regulation applies to the control of electrical, mechanical, hydraulic, pneumatic, chemical, thermal, or other energy. It does not apply to engulfment hazards (liquid or flowable solids), flammable gasses, or other gasses that may be toxic or oxygen displacing.

It is important to understand this distinction because the use of isolation procedures appropriate for the hazards addressed in 1910.147 may not be effective in eliminating other hazards.  “Isolation,” as defined in the Permit Required Confined Space regulation (1910.146) spells out the various measures required to eliminate hazardous energies as covered in the LOTO regulation as well as the types of hazards that are not addressed in that regulation.  You will note that 1910.146 cites LOTO as a means to isolate all sources of energy (emphasis added), but outlines other methods used to isolate the other hazards such as hazardous materials. These isolation procedures include the process by which a permit space is “removed from service” and completely protected against the release of energy and material into the space by such means as: blanking or blinding; misaligning or removing sections of lines, pipes, or ducts; a double block and bleed system; lockout or tagout of all sources of energy; or blocking or disconnecting all mechanical linkages.

By closing and placing a LOTO device on a single valve of a natural gas feed line, you may have controlled the hazard but you have not eliminated it. To provide true isolation (elimination), you will have to employ such means as: blanking or blinding; misaligning or removing sections of lines, pipes, or ducts; or a double block and bleed system.

Download the LOTO tip sheet from NIOSH.

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